1. Field of the Invention
Modern internal combustion engine design is undergoing important changes to meet new Federal standards concerning engine exhaust gas emissions. A major change in engine design recently adopted is the feeding of blow-by gases from the crankcase zone of the engine into the intake air supply of the carburetor rather than venting these gases to the atmosphere as in the past. A further change being adopted involves the recycling of a part of the exhaust gases to the combustion zone of the engine in order to effect a more complete combustion and to further reduce objectionable exhaust emissions. The recycled gases contain substantial amounts of deposit-forming substances which promote the formation of deposits in and around the throttle plate area of the carburetor. These deposits have the effect of restricting the flow of air through the carburetor at idle and at low speeds so that an over-rich fuel mixture results. This condition produces rough engine idling and stalling and serves to increase the harmful exhaust emissions which the engine design changes were intended to overcome.
2. Description of the Prior Art
U.S. Pat. Nos. 3,628,992 and 3,640,676 disclose the use of aminimides for the purpose of shrink-proofing wool and for the bonding of rubber. Detergent motor fuel compositions are the subject of U.S. Pat. Nos. 3,926,578; 3,907,516 and 3,905,781.